package com.itheima;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.BiConsumer;

public class MapDemo {
    public static void main(String[] args) {
        test2();
    }

    private static void text0() {
        Map<String, Double> map = new HashMap<>();
        map.put("张三", 90.0);
        map.put("李四", 80.0);
        map.put("王五", 100.0);
        map.put("赵六", 90.0);
        map.put("田七", 80.0);
/*        map.put("田七", 88.0);*/
        System.out.println(map);

        map.remove("张三");
        System.out.println(map);
/*        map.clear();
        System.out.println(map);*/
        boolean b1 = map.containsKey("李四");
        System.out.println("b1 = "+b1);
        boolean b2 = map.containsKey("80.0");
        System.out.println("b2 = "+b2);

        boolean empty = map.isEmpty();
        System.out.println("empty = "+empty);
        int size = map.size();
        System.out.println("size = "+size);
    }
    public static void test1() {
        Map<String, Double> map = new HashMap<>();
        map.put("张三", 90.0);
        map.put("李四", 80.0);
        map.put("王五", 100.0);
        map.put("赵六", 90.0);
        map.put("田七", 80.0);
        //将map中所有键值取出来放到set集合中
        Set<String> keySet = map.keySet();
        //遍历key集合
        for (String key : keySet) {
            //根据key去找值
            Double value = map.get(key);
            System.out.println(key+"---"+value);
        }
    }
    public static void test2() {
        Map<String, Double> map = new HashMap<>();
        map.put("张三", 90.0);
        map.put("李四", 80.0);
        map.put("王五", 100.0);
        map.put("赵六", 90.0);
        map.put("田七", 80.0);
        //将map集合转成set集合（将map中的key-value绑定成一个对象entry）
        Set<Map.Entry<String, Double>> entrySet = map.entrySet();
        //遍历set集合
        for (Map.Entry<String, Double> entry : entrySet) {
            //更具entry获取key和value
            String key = entry.getKey();
            Double value = entry.getValue();
            System.out.println(key+"---"+value);
        }
    }
    public static void test3() {
        Map<String, Double> map = new HashMap<>();
        map.put("张三", 90.0);
        map.put("李四", 80.0);
        map.put("王五", 100.0);
        map.put("赵六", 90.0);
        map.put("田七", 80.0);
/*        map.forEach(new BiConsumer<String, Double>() {
            @Override
            public void accept(String s, Double aDouble) {
                System.out.println(s+"---"+aDouble);
            }
        });*/
        //lambda
        map.forEach((s, aDouble) -> System.out.println(s + "---" + aDouble));
    }
}
